Chaffetz has invited Comey to testify before the House Oversight Committee next week. FILE - In this May 8, 2017, file photo, then-FBI Director James Comey speaks to the Anti-Defamation League National Leadership Summit in Washington.
Later in the day, he told ABC News' David Muir it "hurts our country terribly" while at a press conference with the Colombian president, he said "I respect the move".
The event that was certain to capture most attention Thursday was set to take place in the afternoon, when Deputy Attorney General Rod Rosenstein, who named Mueller, will brief all 100 members of the Senate on the inquiry.
But anyone hoping a special counsel appointment means the public will ultimately hear a full accounting of the investigation might be disappointed.
"This shuts the whole thing down", said one Republican source, speaking on Congressional efforts to investigate Comey's discussions with Trump.
Democrats disagree. Virginia Sen.
Repeating his assertion that Comey "was very unpopular with most people", Trump said he was dismissed over inaccurate testimony delivered before Congress as well as his faulty decision making during the presidential campaign.
In one of them, Comey wrote that Trump had asked him to end the FBI's investigation into former national security advisor Flynn's dealings with Russian Federation. He has said the claims of Russia's involvement in the election are excuses by Democrats as an explanation for Clinton's upset loss.
In a statement on Wednesday, Trump said an investigation will confirm that "there was no collusion" between his campaign and Russian Federation.
However another answer on that subject seemed both more specific and perhaps ambiguous.
Trump has denounced the FBI investigation as a witch hunt and a charade, and said Wednesday that Mueller would find no evidence that his presidential campaign cooperated with Russian intelligence.More news: Expert finds more North Korea links in ransomware attack
"This is the single greatest witch hunt of a politician in American history!" he Tweeted, also complaining that Hillary Clinton and President Obama were not investigated by a special counsel.
In a statement, Rosenstein said he had made a decision to hand off the high-profile inquiry to a figure outside the normal government chain of command, including the White House, "in order for the American people to have full confidence in the outcome".
Mueller's appointment has been welcomed by politicians from both sides.
If I win-I am going to instruct my AG to get a special prosecutor to look into your situation bc there's never been anything like your lies.
Democratic senators had been prepared to press Mr Rosenstein to take the step of appointing a special prosecutor, but were left praising him instead before his closed-door briefing began.
Mueller was appointed yesterday by Rosenstein, who had faced criticism as the author of a memo that preceded Comey's firing. Trump himself had already contradicted that explanation, telling interviewers earlier that he had already made a decision to dismiss Comey. "I also got a very, very strong recommendation, as you know, from the deputy attorney general, Rod Rosenstein".
Rosenstein, who is meeting with senators on Thursday to discuss Comey's firing, was harshly criticized by Democrats for what they perceived as bowing to Trump's will when he wrote the memo recommending the dismissal.
"That was a poor, poor performance", Trump said.
"Public access to what happened is going to be very limited now because of special counsel", said Sen.
Republican Richard Burr, chairman of the Senate Intelligence Committee, said Flynn's lawyer told the committee he would not honor the panel's subpoena seeking relevant documents.
Congress has the authority to create an independent commission to conduct an investigation, much as it did after the assassination of President John Kennedy and the 9/11 attacks.